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Biomedical subjects

N Labropoulos

Publications and source records attributed to N Labropoulos.

At least 37 records · Page 2Linked to original sources
PubMed2000

Current concepts in chronic venous ulceration.

OBJECTIVES: despite numerous reports on the distribution of reflux in patients with venous ulceration, there is no consensus on the contribution of each venous system. This study was performed to evaluate the distribution of reflux in this group of patients. METHODS: a literature search from 1980 to 1998 was performed. Because duplex scanning is the best method for detecting venous reflux, we only included reports that used this diagnostic modality. All studies with less than 30 ulcerated limbs were excluded. Since most reports did not give detailed data on perforator veins, reflux in these veins was combined with the superficial and deep veins. Documented episodes of superficial or deep vein thrombosis were noted. RESULTS: thirteen studies that included 1249 ulcerated limbs fulfilled the inclusion criteria. The mean age of patients was 59 years (95% CI: 54-63, range: 14-93). Reflux was detected in 1153 (92%) of limbs. Reflux confined to the superficial veins alone was seen in 45% of limbs, in the deep veins alone in 12% and in both the superficial and deep veins in 43% of limbs. The overall involvement of the superficial veins was 88% and of the deep veins 56% (p <0. 0001). A documented episode of deep vein thrombosis was reported in only six of the 13 studies and the incidence was found to be 32%. CONCLUSIONS: reflux in the superficial veins is seen in 88% of limbs with venous ulcers (CEAP classes 5 and 6). Isolated superficial vein incompetence is detected in 45%, while reflux in the deep venous system alone is seen in only 12%. These data have significant clinical implications, since reflux in the superficial system can be easily eliminated by excision of the affected veins.

Chronic Disease↗
PubMed2000

The acute effects of intermittent pneumatic foot versus calf versus simultaneous foot and calf compression on popliteal artery hemodynamics: a comparative study.

INTRODUCTION: Intermittent pneumatic compression (IPC) is currently being investigated with respect to its effect on distal arterial volume flow in patients with peripheral vascular disease. Recently published data have shown a substantial acute enhancement in arterial calf inflow in response to IPC of the lower limb in both intermittent claudication and leg ischemia. PURPOSE: The aim of the study was to compare the immediate effects of intermittent pneumatic foot (IPC(foot)) versus calf (IPC(calf)) versus simultaneous foot and calf compression (IPC(foot+calf)) on popliteal artery hemodynamics in patients with intermittent claudication (Fontaine II) and in normal subjects, using duplex ultrasonography. For this purpose, 25 limbs of 20 healthy subjects (age range [mean], 51-74 [64] years) and 31 limbs of 25 claudicants (age range [mean], 56-81 [66.5] years; resting ankle-brachial indices, 0.38-0.75 [0.55]) were examined in the sitting position with and without IPC compression. RESULTS: Mean popliteal artery flow in healthy subjects increased by 98.8% on application of IPC(foot), 188% with IPC(calf), and 274% with IPC(foot+calf) (all P <.001). Mean flow in claudicants increased by 58% on application of IPC(foot), 132% with IPC(calf), and 174% with IPC(foot+calf) (all P <.001). The mean velocity, peak systolic velocity, and end diastolic velocity displayed a pattern of change similar to that for volume flow in both groups. Pulsatility index decreased in both groups on application of IPC; the lowest values were generated with IPC(foot+calf). CONCLUSION: Of the three compression modes investigated, IPC(foot+calf) was the most effective means of acutely augmenting arterial calf inflow in arteriopaths and normals. The significant increase in end diastolic velocity and decrease in pulsatility index indicate that peripheral vasodilatation is the central mechanism in this impulse-related flow augmentation. Prospective trials are indicated to determine the clinical potential of the long-term effects of IPC(foot+calf) in patients with symptomatic peripheral vascular disease.

Aged↗
PubMed2000

Prevalence of deep venous reflux in patients with primary superficial vein incompetence.

PURPOSE: This prospective study was designed to determine the prevalence of deep reflux and the conditions under which it may occur in patients with primary superficial venous reflux and absence of deep venous thrombosis (DVT). METHODS: We studied 152 limbs in 120 consecutive patients in the standing position who had superficial venous reflux with color flow duplex scanning. Limbs with documented evidence of DVT or post-thrombotic vein wall changes during the examination were studied but not included in the analysis. Limbs were divided into those that had at least reflux in the saphenofemoral, the saphenopopliteal, or the gastropopliteal junction and into those with nonjunctional reflux in the superficial and gastrocnemial veins. Peak velocity and duration of reflux were measured. To examine the recirculation theory, we tested the deep veins by occluding and refluxing saphenous veins 10 cm below the sampling site. RESULTS: Thirteen limbs in 11 patients (9%) were excluded because of previous DVT. Of the remaining 139 limbs, 106 (76%) had junctional reflux. Saphenofemoral junction was involved in 89 limbs (84%), saphenopopliteal junction in 18 (17%), and gastropopliteal junction in 7 (4%). In 33 limbs (24%), reflux was detected in the main trunk or tributaries of the saphenous veins alone with no junctional incompetence. Femoral or popliteal reflux was present in 31 limbs (22%). This reflux was segmental in 27 limbs, and it was limited in the junction in 24 limbs. The mean duration of deep venous reflux was 0.9 seconds, it ranged from 0.6 to 3.7 seconds, and it was significantly shorter than that in the superficial veins (2.6 seconds; P <.0001). In the absence of junctional reflux, the prevalence of deep venous insufficiency (DVI) was significantly lower compared with that in limbs with junctional involvement (2 of 33 vs 29 of 106; P =.038). The mean duration of deep venous reflux in these groups was comparable (0.85 seconds vs 0. 91 seconds; P =.44). Occlusion of the incompetent superficial veins reduced somewhat the duration of the deep venous reflux but did not abolish it (0.88 seconds vs 0.82 seconds; P =.072). The presence of DVI was associated with junctional reflux of high peak velocity and long duration. CONCLUSIONS: The prevalence of DVI in patients with primary superficial venous reflux and without history of DVT is 22%. However, this reflux is segmental, mainly in the common femoral vein, and is of short duration. It is associated with the presence of junctional incompetence that has a high peak velocity and long duration. These findings may explain why surgical correction of superficial reflux abolishes DVI.

Adult↗
PubMed2000

The impact of isolated lesser saphenous vein system incompetence on clinical signs and symptoms of chronic venous disease.

PURPOSE: The purpose of this study was to determine the patterns of isolated lesser saphenous vein (LSV) system incompetence and correlate the distribution and extent of such reflux with symptoms and signs of chronic venous disease (CVD). METHODS: During a 3-year period, 2254 limbs in 1682 patients with signs and symptoms of CVD were evaluated with color flow duplex scanning. Extremities with isolated reflux in the LSV system were selected for this study. Limbs with perforating venous reflux connected to this system only were also included. Limbs that had marked reflux in the greater saphenous or deep vein, that had a documented history of deep venous thrombosis, and that previously underwent surgery or sclerotherapy were excluded. The clinical severity of the limbs was graded with the CEAP classification system. RESULTS: There were 226 limbs in 200 patients with reflux in the LSV system; 61% were female patients with a mean age of 49 years (range, 18-82 years). There were 174 patients (87%) with unilateral and 26 with bilateral disease, and 41% of the limbs belonged in CVD class 2, 26% in class 3, 12% in class 4, 3.5% in class 5, and 3% in class 6. Classes 0 and 1 were present in 14.5% of the limbs. Symptoms were present in 139 limbs (61.5%). Some degree of ache or burning sensation was the most frequent symptom (41%), followed by itching (32%), heaviness (29%), cramps (24%), and restless limbs (18%). Reflux in the main trunk of the LSV was the most prevalent (177 limbs [78%]), followed by the saphenopopliteal junction (146 limbs [64.6%]), the vein of Giacomini (39 limbs [17%]) and the gastrocnemial vein (23 limbs [10%]). Reflux involving both the saphenopopliteal junction and the LSV was seen in 50% of limbs, but almost any other combination of reflux was present, which indicated the complexity of this system. Perforator vein incompetence was detected in 56 limbs (25%). We found 83 perforator veins, resulting in a mean of 1.5 veins per limb. Both the number of incompetent perforator veins and the extent of superficial reflux correlated with clinical severity. Four main types of termination of the LSV were identified with at least nine variations. The LSV was duplicated for at least half of its length in five limbs (2.2%). Nonsaphenous reflux was detected in seven limbs (3.1%). Superficial vein thrombosis in the LSV system was found in eight limbs (3.5%), and in the gastrocnemial vein it was found in four (1.8%). CONCLUSIONS: Isolated LSV system incompetence can cause the entire range of signs and symptoms of CVD. Clinical deterioration is associated with a longer extent of reflux and perforator incompetence. Classes 2 to 4 are the most frequent clinical presentations, whereas classes 5 and 6 are uncommon. The complex anatomy of this system and the great variation in the patterns of reflux warrant the use of color flow duplex scanning before planning treatment.

Adolescent↗
PubMed2000

A prospective study of the effects of irradiation on the carotid artery.

OBJECTIVES/HYPOTHESIS: To prospectively assess the effects of irradiation on the carotid artery in patients with head and neck cancer, as a possibly relevant factor in cancer treatment planning. STUDY DESIGN: Prospective study from a tertiary care academic setting on university (22 patients) and Veterans Affairs (14 patients) hospital patients; 1-year follow-up, including comparison of study data with age-matched and sex-matched control subjects from epidemiological studies. METHODS: Thirty-six patients with head and neck cancer who underwent therapeutic neck irradiation were examined by high-resolution ultrasound before and 1 year after treatment. Twelve patients were also studied at 2 years. Measurements included the intima-media thickness (IMT) of the carotid artery wall, the degree of stenosis as estimated from velocity measurements, and the presence and size of plaque. RESULTS: The pretreatment carotid IMT at baseline was 0.68 mm and was comparable to age-matched and sex-matched control subjects. Significant increase in the IMT was observed on both the left (0.67 vs. 0.84 mm) and the right (0.7 vs. 0.87 mm) sides (P < .001) 1 year after irradiation. In 12 patients who completed 24 months of follow-up the carotid IMT continued to significantly increase statistically compared with that at the first year after treatment (left side, 0.79 vs. 0.85 mm, P = .037; right side, 0.79 vs. 0.95 mm, P = .014). Statistically significant thickening of the carotid wall developed in all 36 patients by 1 year. Two patients experienced post-treatment neurological events and an area of stenosis greater than 75%. CONCLUSIONS: Neck irradiation significantly increases the thickness of the carotid wall during the first year after treatment--on average, 21 times more than in epidemiologically matched control volunteers. This phenomenon should be taken into consideration when planning treatment for the node-negative (NO) neck.

Carcinoma, Squamous Cell↗
PubMed1999

Patterns and distribution of isolated calf deep vein thrombosis.

PURPOSE: In the search for calf deep vein thrombosis (DVT) with color-flow duplex scanning (CFDS), most vascular laboratories investigate only the posterior tibial and peroneal veins. Few laboratories assess the soleal and gastrocnemial veins. This study was designed to determine the patterns and distribution of isolated calf DVT, including the soleal and gastrocnemial veins. METHODS: In the last 3 years, 5250 patients (mean age, 66 +/- 15 years; range, 22 to 93 years) were referred to the vascular laboratory for clinical suspicion of DVT and underwent examination with CFDS. All superficial and deep named veins, excluding the anterior tibial from groin to ankle, were imaged. Of the deep veins in the calf, the peroneal, the posterior tibial, the gastrocnemial, and the soleal veins were examined throughout their length. RESULTS: DVT was detected in 14% of the patients. Isolated calf DVT was detected in 282 limbs of 251 patients (4.8%). No significant difference was noted for the sex (114 men vs 137 women; P =.15) or the limb preference (145 left vs 137 right; P =.5). The peroneal veins were most frequently involved, with 115 limbs (41%) affected. The soleal veins were involved in 109 limbs (39%), followed by the posterior tibial in 105 limbs (37%) and the gastrocnemial in 79 limbs (29%). Thrombus in the soleal vein alone was found in 57 limbs (20%), in the gastrocnemial in 48 limbs (17%), in the peroneal in 41 limbs (15%), and in the posterior tibial vein in 35 limbs (12%). Thrombus confined to a single or paired vein was found in 181 limbs (64%). Thrombus involving two different veins (27%) was the second most frequent pattern, and thrombus in three (7%) or four (1.4%) different veins was less prevalent. Isolated thrombosis in veins not routinely investigated was found in 113 limbs (40%; soleal, n = 57; gastrocnemial, n = 48; soleal + gastrocnemial, n = 8). Multifocal origin of thrombosis, defined as thrombi in two different veins that do not anatomically communicate, was identified in 63 limbs (22%). CONCLUSION: Forty percent of the patients with acute isolated calf DVT would be judged to have normal CFDS examination results if the muscular veins in the calf were not imaged. Multifocal origin of thrombosis was found in 22% of the involved limbs. The prevalence of thrombosis in any calf vein either alone or in combination is comparable. Accordingly, the soleal and gastrocnemial veins should be examined routinely.

Adult↗
PubMed1999

Timing and frequency of perioperative carotid color-flow duplex scanning: A preliminary report.

PURPOSE: The results of intraoperative and early postoperative carotid color-flow duplex scanning (CFS) after endarterectomy were reviewed to determine whether any perioperative studies could be eliminated. METHODS: Patients undergoing carotid endarterectomy with intraoperative CFS between 1986 and 1997 were identified. Early postoperative CFS was performed between 1 day and 3 weeks postoperatively, then it was performed again at 6 months postoperatively. RESULTS: During the study period, 560 patients, 325 men and 235 women, underwent 621 carotid endarterectomies. A satisfactory intraoperative carotid CFS was completed in 611 (98.4%) patients. There were 20 (3.2%) vessels with a major defect that required revision for fronds or flaps (n = 11), retained atheroma (n = 5), low flow (n = 2), high velocity or turbulence (n = 1), or dissection (n = 1). Another 146 vessels (23.5%) had minor defects, such as retained proximal atheromas or small (less than 3 mm) fronds, but were not revised. The remaining 445 vessels were normal. The first postoperative CFS was normal in all the revised carotids and in 138 (94.5%) vessels with minor intraoperative defects. At 6 months, recurrent stenosis (more than 75% area reduction) was identified in 1 of 18 revised carotids (5.5%), 4 of 138 vessels (2. 9%) with minor defects, and 17 of 406 vessels (4.2%) that were normal intraoperatively. The incidence of recurrent stenosis was not significantly different in the three groups (P =.7). CONCLUSION: Intraoperative CFS is useful because major unsuspected defects can be corrected immediately, thus avoiding potential neurologic morbidity. However, the postoperative day 1 CFS can be eliminated in most cases, because it does not provide any relevant clinical information.

Aged↗
PubMed1999

Outcome of moderate carotid artery stenosis in patients who are asymptomatic.

PURPOSE: The incidence rate of disease progression and stroke after the diagnosis of a moderate (50% to 79%) carotid stenosis was determined by means of color-flow duplex scanning. METHODS: During a 4-year period, 344 male veterans with moderate internal carotid artery stenoses, on one or both sides, were examined at regular intervals for a mean period of 25 months. Carotid color-flow scans were obtained semiannually. Clinical follow-up was performed to determine the incidence rate of amaurosis fugax, transient ischemic attacks, nonhemispheric symptoms, and strokes. RESULTS: New neurologic symptoms developed in 75 patients (21.8%). Fifty-one (14.8%) had ipsilateral symptoms during follow-up: 18 amaurosis fugax (5.2%), 14 transient ischemic attacks (4%), 5 nonhemispheric symptoms (1.4%), and 14 strokes (4%). Twenty-four patients (6.9%) had contralateral symptoms: 20 strokes (5.8%) and 4 transient ischemic attacks (1.2%). Life-table analysis showed that the annual rate of ipsilateral neurologic events was 8.1%, and the annual rate of stroke was 2.1%. Seventy-five patients (22%) died in the follow-up period. Disease progression to 80% to 99% stenosis or occlusion occurred in 71 of 458 vessels (15.5%). The internal carotid arteries that showed evidence of disease progression had a significantly higher initial peak systolic velocity (251 vs 190 cm/s; P <.0001) and end diastolic velocity (74 vs 52 cm/s; P < 0.0001). Black patients and patients with ischemic heart disease were at a higher risk for disease progression. We could not identify any atherosclerotic risk factors that reliably predicted patients in whom future ipsilateral neurologic symptoms were more likely to develop. However, there was an increased risk of stroke associated with progression of disease. CONCLUSION: Patients who are asymptomatic and who have moderate carotid stenoses are at significant risk for neurologic symptoms and death, but have a relatively low incidence rate of ipsilateral events. The initial flow characteristics in the stenotic vessel are predictive of future disease progression, but they are not helpful in identifying patients in whom symptoms will develop.

Adult↗
PubMed1999

Primary superficial vein reflux with competent saphenous trunk.

OBJECTIVES: because reflux in superficial vein tributaries is most often collectively reported with the main saphenous veins, its importance remains largely unrecognised. This study was designed to identify the distribution and extent of non-truncal superficial venous reflux and its association with the signs and symptoms of chronic venous disease (CVD). PATIENTS AND METHODS: eighty-four limbs in 62 patients with signs and symptoms of CVD and evidence of reflux on continuous-wave Doppler were subsequently examined with colour-flow duplex imaging. Incompetent superficial vein tributaries were imaged throughout their extent and both ends were identified. Limbs with reflux in the main trunk of the saphenous veins or the deep, perforator or muscular veins, superficial or deep vein thrombosis, injection sclerotherapy, varicose-vein surgery, arterial disease and inflammation of non-venous origin were excluded from the study. The CEAP classification system was used for staging clinical severity of CVD. RESULTS: the prevalence of tributary reflux alone was 9.7% (84/860). Reflux was detected in 171 tributaries. The number of incompetent tributaries ranged from 1 to 5 per limb. Most prevalent were the tributaries to the greater saphenous (111, 65%<0. 0001), followed by those of lesser saphenous (33, 19%) or a combination of both (12, 7%). Incompetent non-saphenous tributaries were uncommon (15, 9%). Among the named tributaries in the lower limb the posterior arch vein was most often incompetent (46, 27%) followed by the anterolateral vein of the thigh (30, 18%), the medial accessory vein (16, 9%) and the anterior arch vein (14, 8%). Reflux in above-the-knee tributaries alone was found in 18 limbs (21%), in below the knee in 23 (28%) and in both sites in 43 (51%). The vast majority of the limbs (71%,p <0.0001) belonged to CVD class 2, 14% in class 3, 9% in class 1 and only 6% in class 4. Class 3 and 4 patients tended to have a longer duration of signs and symptoms, higher number of incompetent tributaries per limb and also a higher prevalence of combined above- and below-knee reflux. CONCLUSIONS: these data indicate that reflux confined to superficial tributaries is found throughout the lower limb. Because this reflux is present without greater and lesser saphenous trunk, perforator and deep-vein incompetence or proximal obstruction, it shows that reflux can develop in any vein without an apparent feeding source. Greater saphenous tributaries are affected significantly more often than those of lesser saphenous, while non-saphenous reflux is uncommon. Most limbs have signs and symptoms of CVD class 2 and 15% belong in classes 3 and 4.

Adolescent↗
PubMed1999

New insights into perforator vein incompetence.

BACKGROUND: there has been much controversy on the role of perforator veins in the development of chronic venous disease (CVD). This study was designed to determine the duration and direction of flow of lower limb perforator veins (PVs) in relation to their location, diameter and competency status of superficial and deep veins, in healthy volunteers and patients with different grades of CVD. PATIENTS AND METHODS: thirty limbs in 15 symptom-free volunteers and 103 limbs in 75 patients with signs and symptoms of CVD were examined with colour-flow duplex scanning. Superficial, perforator and deep veins were studied in the standing and sitting positions. Flow-velocity characteristics, the number and maximum PV diameter at the deep fascia and subfascially were determined. A PV was considered incompetent when the outward flow lasted >0.5 s. RESULTS: 581 PVs were found in the patients and 106 in the volunteers. 163 PVs (28%) were incompetent in the first group and none in the latter. The total number of PVs and the number of incompetent PVs per limb increased significantly with the severity of CVD. The mid-calf area had more competent and incompetent PVs in patients (p <0.01). Mean diameter of incompetent PVs in all the CVD classes was significantly larger than that of competent PVs. Competent PVs tended to be larger with increasing severity of CVD and they were significantly larger in the CVD classes 4 to 6 compared to controls (p <0.01). Subfascial PV diameter was markedly larger than that at the fascial level (p <0.001) regardless of the CVD class. A subfascial PV diameter of >3.9 mm (95% CI 3.4 to 4.4 mm) indicated incompetence. However, the reverse was not true, because about a third of incompetent PVs had a subfascial diameter of <3.9 mm. Both competent and incompetent PVs were smaller when located at the lower thigh, knee, ankle and anterior aspect of the calf than those found in the rest of the calf and mid-thigh (p =0. 03). Both inward and outward flow was found more often in patients than in controls (70/418 vs. 9/106, p =0.048). Most incompetent PVs had outward flow alone (126, 77%). PV incompetence was most frequently associated with reflux in superficial veins (120, 74% (p <0.0001), followed by reflux in both the superficial and deep veins (34, 21%) and reflux in the deep veins alone (9, 5%). The mean duration of outward flow was markedly longer in the presence of both superficial and deep vein reflux compared to superficial (p <0.001) or deep vein reflux alone (p <0.0001). CONCLUSIONS: the number of incompetent PVs and the diameter of both competent and incompetent PV increases with the severity of CVD. Bidirectional PV flow is more common in patients than in normal volunteers, while 77% of the incompetent PVs have outward flow alone. PV incompetence is most often associated with reflux in the superficial veins, indicating that deep venous reflux is rarely the primary cause of PV insufficiency.

Adolescent↗
PubMed1999

Catheter-directed thrombolysis for lower extremity deep venous thrombosis: report of a national multicenter registry.

PURPOSE: To evaluate catheter-directed thrombolysis for treatment of symptomatic lower extremity deep venous thrombosis (DVT). MATERIALS AND METHODS: From a registry of patients (n = 473) with symptomatic lower limb DVT, results of 312 urokinase infusions in 303 limbs of 287 patients (137 male and 150 female patients; mean age, 47.5 years) were analyzed. DVT symptoms were acute (< or = 10 days) in 188 (66%) patients, chronic (> 10 days) in 45 (16%), and acute and chronic in 54 (19%). A history of DVT existed in 90 (31%). Lysis grades were calculated by using venographic results. RESULTS: Iliofemoral DVT (n = 221 [71%]) and femoral-popliteal DVT (n = 79 [25%]) were treated with urokinase infusions (mean, 7.8 million i.u.) for a mean of 53.4 hours. After thrombolysis, 99 iliac and five femoral vein lesions were treated with stents. Grade III (complete) lysis was achieved in 96 (31%) infusions; grade II (50%-99% lysis), in 162 (52%); and grade I (< 50% lysis), in 54 (17%). For acute thrombosis, grade III lysis occurred in 34% of cases of acute and in 19% of cases of chronic DVT (P < .01). Major bleeding complications occurred in 54 (11%) patients, most often at the puncture site. Six patients (1%) developed pulmonary emboli. Two deaths (< 1%) were attributed to pulmonary embolism and intracranial hemorrhage. At 1 year, the primary patency rate was 60%. Lysis grade was predictive of 1-year patency rate (grade III, 79%; grade II, 58%; grade I, 32%; P < .001). CONCLUSION: Catheter-directed thrombolysis is safe and effective. These data can guide patient selection for this therapeutic technique.

Female↗
PubMed1999

Higher prevalence of abdominal aortic aneurysms in patients with carotid stenosis but without diabetes.

BACKGROUND: We compared abdominal aortic aneurysm (AAA) prevalence in 3 groups of patients at the Hines Veterans Affairs Medical Center: (1) patients with 50% or more carotid stenosis, (2) patients with less than 50% stenosis, and (3) patients screened for the Aneurysm Detection and Management (ADAM) study. METHODS: Of all the patients referred to the vascular laboratory for carotid duplex examination during a 12-month period, patients with 50% or more carotid stenosis underwent ultrasonography of the abdominal aorta unless they had a previous scan or previous aortic surgery (group 1, n = 374). Patients with less than 50% carotid stenosis who had been screened for ADAM comprised group 2 (n = 139). They were compared with all patients screened for ADAM at our center during the same time period (group 3, n = 2477). RESULTS: AAA of 3.0 cm or more were present in 18.2%, 12.2%, and 7.2% of groups 1, 2, and 3, respectively; AAA of 4.0 cm or more were present in 8.3%, 5.8%, and 2.1% of groups 1, 2, and 3, respectively. Among patients with carotid stenosis, those patients without diabetes accounted for the observed increase in prevalence (21.9 % > or = 3.0 cm and 10.2% > or = 4.0 cm vs 9.2% and 2.8% in patients with diabetes). CONCLUSIONS: The relative risk of AAA is 2 to 3 times greater in patients with carotid stenosis compared with patients undergoing routine screening. However, only patients without diabetes account for the increased prevalence. Selective AAA screening of patients who are not diabetic with carotid stenosis is recommended.

Aged↗
PubMed1998

Acute effects of intermittent pneumatic compression on popliteal artery blood flow.

OBJECTIVES: To investigate the immediate effects of intermittent pneumatic foot and calf compression (IPFCC) on popliteal artery blood flow in symptom-free volunteers and to determine the reproducibility of color flow duplex imaging in the popliteal artery. DESIGN: Cohort study. SETTING: A university associated tertiary care hospital. PATIENTS: Forty lower limbs of 30 volunteers without symptoms or noteworthy risk factors of peripheral vascular disease. INTERVENTIONS: Popliteal artery blood flow was measured in the sitting position before, during, and after the application of IPFCC using color flow duplex imaging. The interobserver, intraobserver, and between occasion within-subject variability of the popliteal artery blood flow were evaluated in 5 symptom-free volunteers who had at least 5 color flow duplex imaging measurements taken at each of the above time points on 3 different days. MAIN OUTCOME MEASURES: The arterial diameter, peak systolic, end diastolic, and reverse-flow velocities were measured, as well as the duration of forward flow during diastole before, during, and after IPFCC. The same variables were measured in 5 separate volunteers by 3 different observers, on 3 separate days, at 3 separate times to determine reproducibility. RESULTS: Including all types of variability, the popliteal artery blood flow varied from 8% to 39% with a mean value of 19%. Since the diameter of the artery was obtained with less than 5% variability, the time average mean velocity was responsible for the high variation in flow. During application of the IPFCC, the popliteal artery blood flow increased significantly in all subjects (P<.001). The mean increase in the flow was 2.4 times the baseline values. The diameter of the arteries remained unchanged while the time average velocity increased significantly (P<.001). This velocity increase was due to marked elevation in the peak systolic and end diastolic velocities and diminution of the reverse-flow component, as well as a prolongation of the forward flow during diastole. After cessation of the pump, flow returned to baseline levels (P=.41) CONCLUSIONS: Ultrasound-derived popliteal artery blood flow measurements show moderate variability. The application of IPFCC greatly enhances popliteal artery blood flow. The flow increase is due to a dramatic drop in the peripheral vascular resistance as the peak systolic and end diastolic flow velocities increase and the reverse-flow component diminishes. Its role in the treatment of lower extremity occlusive arterial disease needs to be determined.

Adult↗
PubMed1998

Compensatory arterial enlargement is a common pathobiologic response in early atherosclerosis.

BACKGROUND: Human arteries are dynamic conduits that respond to different stimuli by remodeling their structure and size. Arterial dilatation has been shown to occur in moderate and advanced atherosclerosis in studies that evaluated only one artery, either coronary, carotid, or superficial femoral artery (SFA). The purpose of this study was to quantify and compare compensatory arterial enlargement throughout the peripheral vascular system in early atherosclerosis. METHODS: Seventy-two patients (40 male, 32 female, mean age 67 +/- 12 years) underwent transcutaneous B-mode ultrasound imaging during routine examinations. Thirty-nine carotid, 19 aorta, 19 iliac, 23 common femoral (CFA), 21 SFA, and 23 popliteal arteries were longitudinally imaged. Eight healthy volunteers (6 male, 2 female, mean age 27 +/- 2.2 years) had the same arteries evaluated (n = 48). Internal diameter (ID) and external diameter (ED) were measured in disease-free areas and in paired adjacent areas exhibiting increased intima-media thickening (IMT) and small atherosclerotic plaques. The percent change in ID, ED, IMT, and plaque thickness were calculated. RESULTS: There was no observed change in ID or ED in all arteries of the healthy volunteers. When compared with normal vessel segments, all arteries demonstrated a marked decrease in ID and increase in ED in areas of small, hemodynamically insignificant plaque. The aorta had a 6.00% +/- 1.92% increase in ED, which was significantly less than the percent increase in ED observed in carotid (8.14 +/- 4.5%. P = 0.05), CFA (9.73 +/- 3.54%, P = 0.0001), SFA (9.15 +/- 4.25%, P = 0.005), and popliteal arteries (9.67 +/- 4.34, P = 0.002). In all arteries there was a strong correlation between plaque thickness and percent change in ED with the best correlation observed in the popliteal artery (R2 = 0.823, P < 0.0001). IMT was significantly increased in all normal vessel segments of the patients when compared with the healthy volunteers (P < 0.001). CONCLUSION: All peripheral arteries dilate in response to intima-media thickening and early atherosclerotic plaque formation. This adaptive response occurs at the site of the lesion to preserve luminal area. The percent change in ED is strongly related to plaque thickness and is greatest in the more distal arteries.

Adult↗
PubMed1998

Percutaneous ultrasound guided thrombin injection: a new method for treating postcatheterization femoral pseudoaneurysms.

PURPOSE: Since its introduction in 1991, ultrasound guided compression repair of postcatheterization femoral artery pseudoaneurysms has been shown to be effective. Disadvantages of ultrasound guided compression repair include patient discomfort during compression, inability to treat noncompressible pseudoaneurysms, prolonged use of ultrasound equipment and personnel, limited success with patients being treated with anticoagulants, and some early recurrences. We conducted a prospective study to evaluate a new method of treating femoral pseudoaneurysms, percutaneous ultrasound guided thrombin injection. METHODS: Under duplex ultrasound guidance, a 22- or 25-gauge needle was percutaneously positioned within the pseudoaneurysm. Without compressing the pseudoaneurysm, 0.5 to 1 ml thrombin solution (1000 U/ml) was injected to induce thrombosis. Early in the study, the procedure was modified to allow more than one injection. After successful thrombosis, the patients were kept at rest in bed for at least 1 hour. Duplex ultrasound examination was repeated in 1 to 4 days. Distal pulses and ankle-brachial indexes were measured before and after the procedure. RESULTS: Twenty of 21 consecutive pseudoaneurysms were successfully treated with thrombin injection. Fifteen pseudoaneurysms thrombosed immediately (<20 seconds) after one injection. The other five had partial thrombosis after one injection and complete thrombosis immediately after a second injection. The one failure occurred in a patient who had only one injection and then underwent subsequent ultrasound guided compression repair, which failed. No patient required sedation or analgesia during thrombin injection. There were no procedure-related complications and no recurrences. CONCLUSIONS: Percutaneous ultrasound guided thrombin injection appears to be a safe and expeditious method for treating postcatheterization femoral pseudoaneurysms. It has significant advantages with respect to ultrasound guided compression repair or surgical repair.

Adult↗